deposited during the Sinemurian and Pliensbachian stages of the Early Jurassic Period or approximately 199 to 182 million years ago. The Kayenta Formation is part of the Glen Canyon Group that includes formations not only in northern Arizona but also parts of southeastern Utah, western Colorado, and northwestern New Mexico. The formation was primarily deposited by rivers. During the Early Jurassic period, the land that is now the Kayenta Formation experienced rainy summers and dry winters. By the Middle Jurassic period it was being encroached upon from the north by a sandy dune field that would become the Navajo Sandstone. The animals were adapted to a seasonal climate and abundant water could be found in streams, ponds and lakes. Paleofauna Kayentavenator shared its paleoenvironment with other dinosaurs, such as several theropods including Dilophosaurus, Coelophysis kayentakatae, and the "Shake N Bake" theropod, the basal sauropodomorph Sarahsaurus, heterodontosaurids, and the armored dinosaurs Scelidosaurus and Scutellosaurus. The Kayenta Formation has produced the remains of three coelophysoid taxa of different body size, representing the most diverse ceratosaur fauna yet known. The Kayenta Formation has yielded a small but growing assemblage of organisms. Vertebrates present in the Kayenta Formation at the time of Kayentavenator included hybodont sharks, indeterminate bony fish, lungfish, salamanders, the frog Prosalirus, the caecilian Eocaecilia, the turtle Kayentachelys, a sphenodontian reptile, various lizards, and the pterosaur Rhamphinion. Also present were the synapsids Dinnebitodon, Kayentatherium, Oligokyphus, morganucodontids, the possible early true mammal Dinnetherium, and a haramiyid mammal. Several early crocodylomorphs were present including Calsoyasuchus, Eopneumatosuchus, Kayentasuchus and Protosuchus. Vertebrate trace fossils from this area included coprolites and the tracks of therapsids, lizard-like animals, and dinosaurs, which provided evidence that these animals were also present. Non-vertebrates in this ecosystem included microbial or "algal" limestone, freshwater bivalves, freshwater mussels and snails, and ostracods. The plant life known from this area included trees that became preserved as petrified wood. References Prehistoric tetanurans Early Jurassic dinosaurs of North America Fossil taxa described in 2010 Paleontology in Arizona Kayenta Formation